Method of making a power transmission belt/belt sleeve and a power transmission belt

ABSTRACT

A method of making a power transmission belt/belt sleeve by bias cutting sides thereof using a cutter. A belt/belt sleeve preform is trained around at least two spaced shafts and driven as the sides are reconfigured by the cutter. The cutter may reside within a cutting space bounded by an inner circumference of the traveling belt/belt sleeve preform. The belt/belt sleeve preform has a starting shape wherein spaced sides thereof are parallel to each other. Parts of the sides may be maintained parallel after the bias cutting is performed. A power transmission belt with bias cut side surfaces is also contemplated.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to power transmission belts and, moreparticularly, to a power transmission belt having a bias cut sidesurface. The invention is further directed to a method formaking/forming a power transmission belt/belt sleeve, including thosehaving a bias cut side surface.

2. Background Art

It is common to manufacture V-belts by initially forming a belt sleeveconsisting of rubber and other component parts. The belt sleeve isvulcanized and thereafter cut to produce individual belts having atrapezoidal cross-sectional shape. This conventional manufacturingprocess often results in structural variations that may compromise theperformance of the belt and its operation. The length andcross-sectional shape of the belt may vary due to thermal shrinkage ofmaterial defining the belt. Load carrying cords, between tension andcompression sections, may be less than optimally located. Other flawsmay occur in the machining process that result in the production of abelt with less than the desired quality.

Of these problems, the variation in cross-sectional size and shape is ofparticular concern. This condition may cause the position of a beltwithin a cooperating pulley groove to fluctuate in a radial directionrelative to the pulley axis. This fluctuation may cause vibrations to beinduced during running. This condition may also cause fluctuation in thebelt tension, which may cause vibration of pulleys, around which thebelt is trained, and associated machinery.

To address the above problem, it is known to subject the individualV-belts, cut from a sleeve, to a sanding process. An exemplary structureand method for accomplishing this are shown in the Official Gazette ofJapanese Patent No. 3553371. The cut belt is trained around a pair ofpulleys and driven in an endless travel path. As the belt is traveling,the sides are polished to be brought within dimensional tolerances.

One advantage associated with polishing the side surfaces is that asubstantial area of short staple reinforcing fibers becomes exposed atthe belt side surfaces. As a result, the coefficient of friction betweenthe side surfaces and cooperating pulleys is decreased, as a result ofwhich noise generation, particularly at startup, is maintained generallyat an acceptably low level. On the other hand, as the belt slips, due tothe reduced coefficient of friction, unwanted abrasion and heatgeneration may occur.

In an alternative process, the vulcanized sleeve can be turned insideout and placed on a mandrel. While rotating the mandrel, V-shapedgrooves can be cut into the sleeve using a grinding stone, after which acutter is employed to separate the individual belts. An exemplarystructure and method of forming belts in this manner are described inU.S. Pat. No. 3,818,576.

A further apparatus and method for forming V-belts are shown in theOfficial Gazette of JP-B-4-2425. An apparatus is disclosed thereinincluding a driving pulley and a driven pulley around which a beltpreform is trained for movement in an endless path. The driven pulley ismovable along a guide rod. A pair of rotatable cutting blades are usedto reconfigure/form the belt sides. A pushing roller is provided at acutting location to bear against a back face of the belt to reinforcethe same as the cutting blades are pressed against the belt. The cuttingoccurs as the belt is driven and the cutting blades rotate.

With this apparatus, the rotary cutting blades are arranged relative toeach other such that both sides of the belt are interposed between therotary cutting blades to be simultaneously operated upon. As a result,relatively large components may be required for the cutter, includingthe cutting blades, to effect the required cooperative movement betweenthe belt and the cutter. Generally, with increased complication and sizeof an apparatus, weight and manufacturing expense correspondinglyincrease.

In Official Gazette of JP-A-55-28883, an apparatus and method are shownwherein cutting of a belt sleeve is carried out so that the finishedforms of adjacent belts coincide at their sides. As a result, the amountof material that is removed and must be disposed of, or otherwisehandled, is reduced compared to a system wherein there is a spacingbetween adjacent belts.

With the sides of adjacent belts coincident, a certain amount ofmaterial can be saved. However, there is still a significant amount ofscrap that results. Thus, there is still room for improvement withrespect to minimizing scrap generation.

This latter method is preferable in this regard to the previouslydescribed methods, which generate considerable scrap or waste material.For example, the cutting blades may remove a significant, ring-shapedscrap at each side surface. Scrap generated through grinding, shaving orpolishing may likewise be significant in the above-described methods.Generally, there is a strong desire to reduce the quantity of scrapgenerated during the belt forming process both to save material and timeas well as avoid inconvenience associated with handling the generatedscrap.

It is also an objective of designers of this type of equipment toprovide structure that is compact and affordable, yet capable ofproducing high quality power transmission belts. Another aim ofdesigners of such systems is to allow these processes to be carried outin a time efficient manner.

SUMMARY OF THE INVENTION

In one form, the invention is directed to a method of making a powertransmission belt/belt sleeve. The method includes the steps of:providing an endless belt/belt sleeve preform having an inside, anoutside, and spaced sides and further consisting of a compression rubberlayer, a tension rubber layer, and at least one load carrying memberbetween the inside and outside of the belt/belt sleeve preform; trainingthe belt/belt sleeve preform around at least first and second shaftshaving first and second axes; driving at least one of the shafts tothereby cause the belt/belt sleeve preform to travel in an endless path;providing a pushing components at one of the inside and outside of thebelt/belt sleeve preform at a first location; providing at least oneguide element to bear against at least one of the sides of the belt/beltsleeve preform to confine movement of the belt/belt sleeve preform;providing a cutter; and directing the cutter against the belt/beltsleeve preform from the other of the inside and outside of the belt/beltsleeve preform at or adjacent to the first location so that the one ofthe inside and outside of the belt/belt sleeve preform is supported bythe pushing component, to thereby reconfigure the belt/belt sleevepreform.

In one form, the first shaft has a small diameter portion between spacedlarger diameter portions and the step of training the belt/belt sleevepreform involves placing the belt/belt sleeve preform between the spacedlarger diameter portions.

The step of training the belt/belt sleeve preform may involve placingthe tension rubber layer and at least a part of the compression rubberlayer between the spaced larger diameter portions.

In one form, the first and second axes are substantially parallel andthe step of directing the cutter involves causing the cutter to bias cutthe compression rubber layer relative to a reference plane that isorthogonal to the first and second axes.

In one form, the step of providing an endless belt/belt sleeve preforminvolves providing an endless belt/belt sleeve preform wherein thespaced sides are substantially parallel to the reference plane.

The step of providing a belt/belt sleeve preform may involve providing abelt/belt sleeve preform with a width at least nominally equal to adesired width of a completed power transmission belt.

The step of providing a pushing component may involve providing apushing roller.

The step of providing at least one guide element may involve providingat least one guide roller at each of the spaced sides of the endlessbelt/belt sleeve preform.

The step of providing a pushing component may involve providing apushing component at a location so that the pushing component cannot becontacted by the cutter as the cutter is directed against the belt/beltsleeve preform.

The method may further include the step of changing a spacing betweenthe larger diameter portions of the first shaft to accommodate a widthof the belt/belt sleeve preform.

In one form, the load carrying member has an inside and an outside andthe step of providing a belt/belt sleeve preform involves providing abelt/belt sleeve preform with a tension section defining the outside ofthe belt/belt sleeve preform and a compression section defining theinside of the belt/belt sleeve preform. A distance from the outside ofthe belt/belt sleeve preform to the outside of the load carrying memberis defined as L. The spaced sides of the belt/belt sleeve preform arebias cut relative to a plane bisecting the belt/belt sleeve preformbetween the spaced sides, from a boundary location that is spaced fromthe outside of the belt/belt sleeve preform by 90-100% of the distance Lto the inside of the belt/belt sleeve preform.

The step of directing the cutter may involve causing the cutter toseparate an endless portion of the belt/belt sleeve preform that, uponbeing separated, is caused to embrace one of the spaced larger diameterportions of the first shaft so as to follow rotational movement of thefirst shaft.

The step of providing an endless belt/belt sleeve preform may involveproviding short fibers with lengths extending between the sides of thebelt/belt sleeve preform that are exposed at the bias cut spaced sidesin the compression rubber layer.

In one form, the bias cut spaced sides each has an area and the step ofproviding short fibers involves providing short fibers in an amount suchthat a combined area of the short fibers exposed at each spaced side isequal to 20-70% of the area of each spaced side that is bias cut.

The step of providing a belt/belt sleeve preform may involve providing abelt/belt sleeve preform with a length and cogs spaced at regularintervals along the length of the belt/belt sleeve preform.

The step of training the belt/belt sleeve preform may involve trainingthe belt/belt sleeve preform to define an inner circumference withinwhich a cutting space is defined. The step of directing the cutter mayinvolve moving the cutter (a) in one direction within the cutting spaceto reconfigure one of the spaced sides of the belt/belt sleeve preformand (b) generally oppositely to the one direction within the cuttingspace to reconfigure the other of the spaced sides of the belt/beltsleeve preform.

The step of providing a cutter may involve providing a cutter with firstand second cutting blades that can be fixed relative to each other andto respectively configure the one and the other of the spaced sides ofthe belt/belt sleeve preform.

In one form, the step of providing a cutter may involve providing acutter with first and second disk-shaped cutting blades, each having anaxis, wherein the first and second cutting blades are radiallyoverlapped with the axes of the first and second cutting blades beingnon-coincident.

The method may further include the steps of changing the cutter from afirst state, pivoting the first disk-shaped cutting blade around itsaxis, and thereafter changing the state of the cutter back into thefirst state to fix a position of the first disk-shaped cutting blade.

The step of providing a pushing component may involve providing apushing component to reinforce the belt/belt sleeve preform with thecutter moving in the one direction. The method may further include thestep of providing a second pushing component to reinforce the belt/beltsleeve preform with the cutter moving oppositely to the one direction.

In another form, the invention is directed to a method of making a powertransmission belt/belt sleeve. The method includes the steps of:providing an endless belt/belt sleeve preform having an inside, anoutside, and spaced sides, and consisting of a compression rubber layer,a tension rubber layer, and at least one load carrying member betweenthe inside and outside of the belt/belt sleeve preform and having aninside and an outside, and wherein a distance from the outside of thebelt/belt sleeve preform to the outside of the load carrying member isdefined as L; and bias cutting the spaced sides relative to a planebisecting the belt/belt sleeve preform between the spaced sides from aboundary location that is spaced from the outside of the belt/beltsleeve preform by 90-100% of the distance L, to the inside of thebelt/belt sleeve preform.

The step of providing a belt/belt sleeve preform may involve providing abelt/belt sleeve preform with spaced sides that are substantiallyparallel to each other.

The method may include the step of training the belt/belt sleeve aroundfirst and second spaced shafts. In one form, the step of bias cuttinginvolves bias cutting the spaced sides at a location between the firstand second shafts wherein the belt/belt sleeve preform is under tension.

The method may further include the step of providing a pushing componentat a first location to reinforce the belt/belt sleeve as the biascutting is performed.

The step of training the belt/belt sleeve preform may involve trainingthe belt/belt sleeve preform to define an inner circumference withinwhich a cutting space is defined. The step of bias cutting may involvebias cutting using a cutter. The method may further include the steps ofmoving the cutter (a) in one direction within the cutting space toreconfigure one of the spaced sides of the belt/belt sleeve preform and(b) generally oppositely to the one direction within the cutting spaceto reconfigure the other of the spaced sides of the belt/belt sleevepreform.

The invention is further directed to a power transmission belt having abody with an inside, an outside, and spaced sides and consisting of acompression rubber layer, a tension rubber layer, and at least one loadcarrying member between the inside and outside of the body. The loadcarrying member has an inside and an outside. A distance from theoutside of the body to the outside of the load carrying member isdefined as L. The spaced sides of the body are bias cut relative to aplane bisecting the body between the sides of the body from a boundarylocation, spaced from the outside of the body by 90-100% of the distanceL, to the inside of the body.

In one form, there are short fibers in the body having lengths extendingbetween the sides of the body.

The short fibers may reside in the compression rubber layer.

The fibers may be exposed at the sides of the body where the body isbias cut.

In one form, the sides of the body where the body is bias cut each hasan area and the short fibers are exposed at each side of the body overan area equal to 20-70% of the area of the sides of the body that arebias cut.

The short fibers may be flush with the sides of the body.

In one form, the body has a length and cogs are formed at regularintervals along the length of the body.

The power transmission belt may be one of (a) a V-belt, (b) a V-ribbedbelt, and (c) a flat belt.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a power transmission belt of thetype that can be made according to the present invention;

FIG. 2 is a fragmentary, perspective view of one form of powertransmission belt, made according to the present invention;

FIG. 3 is an enlarged view of the portion of the side of the powertransmission belt in FIG. 2 within the circle in FIG. 2;

FIG. 4 is a fragmentary, side elevation view of a mold with componentsof a belt/belt sleeve preform formed thereon;

FIG. 5 is a perspective of a cog pad used to form a belt/belt sleevepreform;

FIG. 6 is an enlarged, fragmentary, elevation view of a portion of amold with a reinforcing fabric layer being placed thereagainst through apinion roller;

FIG. 7 is a side elevation view of a mold in which a compression rubberlayer is formed therearound preparatory to treatment under controlledtemperature and pressure conditions;

FIG. 8 is a view as in FIG. 7 after the compression rubber layer hasbeen treated;

FIG. 9 is a fragmentary, side elevation view of a mold with belt/beltsleeve components, used to make a belt as in FIG. 1, built uptherearound;

FIG. 10 is a cross-sectional view of a squared belt preform used toconstruct the belt in FIG. 2;

FIG. 11 is a schematic, elevation view showing one form of belt formingapparatus, according to the present invention;

FIG. 12 is a view as in FIG. 11 from a perspective turned 90° from thatin FIG. 11;

FIG. 13 is a view as in FIG. 11 wherein a belt/belt sleeve preform hasbeen cut and scrap pieces removed during cutting remain intact;

FIG. 14 is a cross-sectional view of the belt forming apparatus takenalong line 14-14 of FIG. 13;

FIG. 15 is a cross-sectional view of the belt forming apparatus takenalong lines 15-15 of FIG. 13;

FIG. 16 is an enlarged, fragmentary, perspective view of a shaft on theinventive belt forming apparatus with a belt/belt sleeve preform trainedtherearound and scrap pieces cut therefrom and embracing the shaft;

FIG. 17 is a perspective view of a modified form of belt formingapparatus, according to the present invention;

FIG. 18 is a cross-sectional view of a part of the belt formingapparatus taken along line 18-18 of FIG. 17; and

FIG. 19 is an enlarged, fragmentary, perspective view of a cutter on theapparatus in FIGS. 17 and 18 and an elongate support arm therefor.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention can be practiced with virtually any type of powertransmission belt, as shown generically at 8 in FIG. 1, having spacedpulley-engaging side surfaces 10, 11.

One specific, exemplary form of power transmission belt, made accordingto the present invention, is shown at 12 in FIGS. 2 and 3. The powertransmission belt 12 is what is commonly referred to as a raw edge,cogged belt, typically used as a speed changing belt on variousequipment, such as snowmobiles, scooters, and general industrialmachinery. The belt 12 has a body 14 with an inside 16, outside 18, andoppositely facing, spaced sides 20,22.

The body 14 consists of a compression rubber layer 24, a tension rubberlayer 26, and a cushion rubber layer 28 between the compression andtension rubber layers 24,26. Spirally wrapped, load carryingmembers/cords 30 define the belt neutral axis, outside of which atension section at 32 is formed and inside of which a compressionsection at 34 is formed. The load carrying cords 30 may be made fromfibers and are embedded in the cushion rubber layer 28. A reinforcingcloth layer 36 is provided on the outside 38 of the tension rubber layer26. A like reinforcing cloth layer 40 is provided on the inside 42 ofthe compression rubber layer 24.

The body 14 has an endless length, as indicated by the double-headedarrow LL. Cogs 44 are arranged at regular intervals along the length ofthe body 14.

Side surface portions 46,48 are square cut, i.e., flat and substantiallyparallel to each other, in the tension section 32. Side surface portions50,52 are bias cut with respect to a reference plane P bisecting thebody 14 between the sides 20,22 thereof. The square cut side surfaceportions 46,48 are substantially orthogonal to the outside surface 54 ofthe body 14, as defined by the reinforcing cloth layer 36.

In FIG. 1, the dimension “L” represents a distance from the outsidesurface 54 of the body 14 to the outside 56 of the load carrying cords30. The vertical dimension of the bias cut side surface portions 50,52is identified by the dimension L1. The transition between the square cutside surface portions 46,48 and bias cut side surface portions 50,52occurs at a boundary location BL. The vertical dimension of the squarecut side surface portions 46,48 is identified by L3. According to theinvention, the dimension L3 is equal to 90-100% of thedistance/dimension L.

In this embodiment, the sides 20,22 each makes an angle θ with respectto vertical. θ is preferably from 20-60°. A belt of this type isreferred to as a wide angle belt.

In the embodiment shown in FIGS. 2 and 3, the boundary location BL iscoincident with the outside of the load carrying cords 30. That is, L3is equal to L, or in other words, the transition location between theside surface portions 46, 48 and 50, 52 is spaced from the outsidesurface 54 a distance L. With the belt 12 in this shape, the pitch lineof the load carrying cords 30 will always come into contact with acooperating pulley 57. Accordingly, the power transmission efficiency ofthe belt 12 can be maintained at a high level. At the same time, theamount of scrap produced in forming the belt 12 can be maintained at arelatively low level.

In the event that the boundary location BL is shifted upwardly from theoutside 56 of the load carrying cords 30 such that the spacing of theboundary line BL from the outside surface 54 is less than 90% of L,generally no problems are caused with respect to the power transmissionefficiency for the belt 12. However, this condition is not preferred inthat a larger quantity of shaving scrap is generated during beltformation.

In the event that the boundary location BL is moved, such that thespacing of the boundary location BL from the outside surface 54 isgreater than 100% of L, the load carrying cords 30 become separated fromthe sides of the cooperating pulley 57, as a result of which powertransmission efficiency for the belt 12 may deteriorate. Belt jumpingmay also occur. Further, the shaved scrap produced during formation ofthe belt 12 may be so thin that it is prone to breaking loose as thebelt preform travels during the formation process.

As seen in FIGS. 2 and 3, short, staple, reinforcing fibers 58 reembedded in the compression rubber layer 24 with their lengths extendinggenerally sideways. The end surfaces 60 of the fibers 58 that areexposed at the sides 20,22 are preferably cut to be flush at the sides20,22. As a result, the combined areas of the exposed fiber surfaces 60can be controlled relative to the overall surface area of the sides20,22, within which the fibers 58 are provided, to increase as desiredthe friction coefficient between the sides 20,22 and the cooperatingpulley 57. As a result, abrasion at initial startup and heat generationas a result of belt slippage can be controlled. A belt of highdurability can be made with this construction.

Preferably, the total area of the exposed fiber surfaces 60 is between20-70% of the entire area of the bias cut side surface portions 50,52.If this ratio is lower than 20%, the friction coefficient between thesides 20,22 and cooperating pulley 57 is increased, as a result of whichnoise may be generated by adhesive abrasion. Further, since thecumulative area of the exposed fiber surfaces 60 is relatively small,the reinforcing effect from the fibers 58 may be inadequate.

On the other hand, if the ratio exceeds 70%, the belt 12 will have atendency to slip relative to the pulley 57, which causes abrasion andfrictional heat generation.

The invention contemplates that any load carrying member(s) can be usedbetween the tension and compression sections 32,34. In this embodiment,load carrying cords 30 are shown which may be made from polyesterfibers, aramid fibers, and/or glass fibers. It is desirable that thecords have a total denier of 4,000-8,000 in which polyester fiberfilament groups, having main components that areethylene-2,6-naphthalate, are twisted together and subjected to adhesiontreatment. The ratio of the belt slippage can thus be controlled.Additionally, the belt life can be maintained at an adequate level. Inone exemplary embodiment, the final twist number of the cords 30 is10-23/10 cm, with the initial twist number being 17-38/10 cm.

In the event that the total denier is lower than 4,000, the modulus ofthe load carrying cords 30 may become too low. If the total denierexceeds 8,000, the belt 12 may become too thick, as a result of whichbending properties are compromised and the belt 12 may be prone tobending fatigue.

The rubber in the tension and compression sections 32,34 may be the sameor different. Suitable rubbers are: natural rubber, butyl rubber,styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber,alkylated chlorosulfunated polyethylene, hydrogenated nitrile rubber,mixed polymer of hydrogenated nitrile rubber and unsaturated carboxylicacid metal salt. The above components may be used alone or in anycombination.

The fibers 58 may be aramid fibers, polyamide fibers, polyester fibers,cotton, etc. The preferred lengths of the fibers 58 depend upon thefiber composition. Generally, a preferred length is 1-10 mm. Forexample, if aramid fibers are used, a length of 3-5 mm is preferred. Inthe case of polyamide fiber, polyester fiber, and cotton, a length of5-10 mm is preferred.

As noted above, the lengths of the fibers 58 are oriented generally fromside to side. Assuming directly side to side is taken to be at a 90°angle, it is preferred that the lengths of the fibers 58 be oriented ina range of 70° to 110°.

Preferably, the tension rubber layer 26 does not include any reinforcingfibers 58. Reinforcing fibers 58 may be provided in the cushion rubberlayer 28, however, more preferably, no fibers are provided therein.

The cloth layers 36,40 may be made of cotton, polyester fiber, nylon, orthe like, that is plain woven, twill woven or sateen woven. The clothlayers 36,40 may be wide angle canvas, with a crossing angle of warp andweft in the range of 90-120°. The cloth layers 36,40 may be subjected toRFL treatment, after which the cloth is friction coated with rubber. Inone embodiment, RFL solution is made in such a manner that an initialcondensate of resorcinol and formaldehyde is mixed with latex. Suitablelatex includes: chloroprene, styrene-butadiene-vinylpyridine ternarycopolymer, hydrogenated nitrile rubber, and NBR.

One exemplary method of forming the belt 12 is shown in FIG. 4. In FIG.4, the body 14 is defined by serially building up the compression rubberlayer 24, loading carrying cords 30, and tension rubber layer 26 upon amold 62. The mold 62 has a peripheral surface 64 with alternatingprojections and grooves 66,68 at regularly spaced intervals around thesurface 64.

As an alternative to the mold construction shown in FIG. 4, a mold canbe used with an inner mother mold in which corresponding projections andgrooves are alternatingly formed in a circumferential direction atregular intervals.

As a further alternative, as shown in FIG. 5, a pre-formed cog pad 70may be used to form the belt 12. The cog pad 70 is made as follows. Inone exemplary embodiment, one or several sheets of reinforcing cloth, anunvulcanized rubber sheet, which will become part of the compressionrubber layer 24, and an unvulcanized rubber sheet, which will become thecushion rubber layer 28, are laminated upon each other and set on aflat, metallic mold (not shown) which is preformed with projections andgrooves in a desired alternating pattern. This assembly is thenpressurized, as a result of which the cogs 44 and grooves 74, betweenadjacent cogs 44, are formed by the mold.

One end 76 of the cog pad 70 is bias cut at a cog crest 78 to an angleα, which is preferably 0-40°. The cog pad 70 is inverted and the otherend 80 likewise bias cut in the same manner in a reversely inclineddirection at a spaced crest 82. Through this arrangement, the ends 76,80can be butted into close contact with each other to produce an endlessconfiguration for the cog pad 70.

The mold 62 of FIG. 4 can then be attached to a forming machine (notshown). The cog pad 70 in turn be engaged with the peripheral surface 64of the mold 62 so that the cogs 44 and grooves 74 complementarily matewith the projections 66 and grooves 68 on the mold 62. The length of thecog pad 70 is controlled so that the cog pad 70 will extend continuouslyaround the mold 62 with the ends 76,80 butted. Once the cog pad 70 isput in place, the load carrying cords 30 are spirally wrapped.Thereafter, from one to several sheets of reinforcing cloth, and anunvulcanized rubber sheet, which will become the tension rubber layer26, are wound over the load carrying cords 30. Through this procedure, abelt/belt sleeve preform assembly is constructed.

Once these steps are completed, the assembly is surrounded by a jacket,placed in a vulcanization vessel and vulcanized using conventionalprocesses. After the completion of vulcanization, the jacket andbelt/belt sleeve preform are separated from the mold 62.

As a further method of making a belt/belt sleeve preform, reinforcingcloth/canvas 40 may be attached in the grooves 68 of the mold 62 as by apinion roller, as hereinafter described. A rubber sheet is woundthereover and the end faces thereof butted to form an endless body. Thisrubber sheet is then heated and pressurized from the outer circumferenceand preliminarily fit at the peripheral surface 64 of the mold 62 in ameshing fashion, as described above. On the exposed surface of therubber layer which overlies the mold 62, load carrying cords and aseparate rubber sheet are successively wound to complete the belt/beltsleeve preform.

In all embodiments, as described herein, the width of the startingpreform may be equal to the width of a single belt or may have a widthsufficient that several belts can be cut therefrom. For purposes ofsimplicity, the preform will be generically identified as a “belt/beltsleeve” preform in the written description and claims herein, with itbeing understood that this term will encompass any different width ofsleeve be it for a single belt or multiple belts. The belt/belt sleevewill hereinafter be identified with the reference numeral “12” with thecorresponding preform identified with the reference numeral “12′”.

The application of the reinforcing cloth layer 40 to a mold 84,referenced above, will be described in detail with respect to FIG. 6. Arubber adhesive 85, such as mucilage, is coated on projections 86 andgrooves 88 on the peripheral surface 90 of the mold 84 with a sprayer,brushes or rollers. In this embodiment, a cylindrical mother mold isattached to a metallic mold. Then the reinforcing cloth layer 40, whichmay or may not have been subjected to adhesion treatment, is applied tothe peripheral surface 90. Thereafter, a pinion roller 92 is movedradially inwardly with one of a series of teeth 94 thereon registeredwith one of the grooves 88 on the mold 84. The mold 84 is thereafterrotated about its axis 96 in the direction of the arrow 98. Thereinforcing cloth layer 40, at the projection 86 shown at A, is pressedagainst on one side of a crest region thereon by a round, peripheralsurface 100 on the pinion roller 92, from which the teeth 94 project. Asthis occurs, the free end 102 of the engaged tooth 94 extends into thegroove 88 to press the reinforcing cloth layer 40 flushly against theperipheral surface 90 at the bottom of the groove 88.

As the mold 84 and pinion roller 92 continue to relatively rotate fromthe FIG. 6 position, the peripheral surface 100 of the pinion roller 92captures the reinforcing cloth layer 40 against the projection 86 at Aon the other side of the crest region, thereby securing the cloth layer40 thereat before the upstream tooth 94 moves into the groove 88 at Bafter which the surface 100 presses the cloth layer 40 against a side ofthe crest on the projection 86 at C.

Through this sequence of events, the reinforcing cloth layer 40 can besmoothly and consistently conformed to each groove 88 without forciblyelongating the reinforcing cloth layer 40. With one active tooth 94 in agroove 88, the adjacent teeth 94 are separated from the reinforcingcloth layer 40 so as to not tend to stretch the same. Thus there islittle likelihood that the reinforcing cloth layer 40 will deform orfloat. By repeating this action through continued meshed rotation of themold 84 about the axis 96 and pinion roller 92 about the axis 104, thereinforcing cloth layer 40 becomes tightly conformed to the entireperipheral surface 90 of the mold 84. One to four plies of thereinforcing cloth layer 40 may be applied in this manner. At theconclusion of this process, the reinforcing cloth layer is cut and thecut end stuck to the mold 84.

The adhesive used to secure the reinforcing cloth layer 40 may consistof different rubber compositions dissolved in solvent, such asmethylethylketone (MEK) and toluene that are mixed with each other. Withthis rubber adhesive, the reinforcing cloth layer 40 can be tightly andsecurely held to the peripheral surface 90 of the mold 84.

As shown in FIGS. 7 and 8, the compression rubber layer 24 is applied tothe mold 84 by wrapping the same therearound and butting cut end faces106, 108 together to form an endless shape. At this point, thecompression rubber layer 24 is unvulcanized. The ends 106, 108 thereofare preferably cut to facilitate connection and maintain integrity at ajoint 110. A pressurizing jig (not shown) can be used to tighten theconnection at the joint 110. Additionally, heating and pressurizationmay be carried out, as by a heating press (not shown), to morepositively secure the ends 106,108.

In one embodiment, the heating and pressurization are carried out at atemperature of from 80-120° C., with a surface pressure of 1 to 2 kg/cm²for 10-30 seconds. Preferably, the joint 110 is located at a groove 88on the mold 84. If the joint 110 is located at a projection 86, thejoint 110 tends to move towards the bottom of a cog 44 in the completedbelt 12. As a result, there is a greater tendency for cracking to startat the joint 110.

A resin film, having good heat resistance and good mold releasingproperties, is wound around the compression rubber layer 24. Preferably,a single ply is used. The resin film may be made of polymethylpentene orpolyethylene terephthalate, which is an adhesion preventing agent.

The compression rubber layer 24 on the mold 84 is prepared forvulcanization using a vulcanization jacket 116. This assembly is thenplaced in a vulcanization vessel and treated for 5-10 minutes at atemperature of 160-180° C. with an external pressure of 0.8 to 0.9 MPa.Through this process, the compression rubber layer 24 conforms to themold 84, as shown in FIG. 8. During the vulcanization process, no cracksare generated at the joint 110.

It should be understood that the mold attaching process can be conductedin such a manner that the outside of the compression rubber layer 24 isheated and pressurized by a band system or a press system without usinga vulcanization jacket and vessel.

In FIG. 9, the mold 84, upon which the compression rubber layer 24 isformed, as previously described, is set in a forming machine (notshown), after which the load carrying cords 30 are spirally wrappedtherearound. Thereafter, the cushion rubber layer 28 is applied followedby the tension rubber layer 26 and the reinforcing cloth layer 36. Themold 84 can then be removed from the forming machine and set on asupport table engaged by the aforementioned vulcanization jacket 116.

This assembly can then be placed in a vulcanization vessel withvulcanization carried out in a conventional manner. At the completion ofvulcanization, the jacket 116 is separated from the mold 84 and thebelt/belt sleeve preform 12′ in turn separated from the mold 84.

Next, the resulting belt/belt sleeve preform 12′ is set on a mandrel andsquarely cut to a predetermined width corresponding to a desired widthfor the completed belt 12. Accordingly, the resulting belt preform 12′is rectangular, as shown in FIG. 10. The single belt preform 12′ is thenmounted on a belt forming apparatus 120, as shown in FIGS. 11-16. Thesides 20′,22′ of the belt preform 12′ are then bias cut by a cutter,consisting of pair of cutting blades 124, 124′, which separate anendless ring of scrap that is removed from the completed belt 12. Thebelt 12 is completed by forming the sides 20,22 with the resultingsquare cut side surface portions 46,48 and bias cut side surfaceportions 50,52 (see FIG. 2).

Details of one preferred form of belt forming apparatus 120 will now bedescribed with respect to FIGS. 11-16. The belt forming apparatus 120consists of spaced shafts 126,128, which are respectively rotatablearound spaced, parallel axes 130,132. The belt/belt sleeve preform 12′is trained around the shafts 126,128. The shaft 126 is driven by a motor134 in the direction of the arrow A around the axis 130 and therebycauses the belt/belt sleeve preform 12′ to move in an endless travelpath, as indicated by the arrows A1.

Both of the shafts 126,128 project from left to right in FIGS. 11 and 13in cantilevered fashion. The shaft 126 includes a mounting assembly 136with a small diameter portion 138 bounded by larger diameter portions140,142. The larger diameter portion 140 is defined by a stationaryflange 144, with the larger diameter portion 142 defined by a movableflange 146. The outside surface 54 of the belt preform 12′ (FIG. 10)bears on a radially outwardly facing surface 148 at the small diameterportion 138. Corners 150,152 on the flanges 144,146, respectively, areradiussed/rounded to facilitate guiding of the belt/belt sleeve preform12′ thereover to against the surface 148 between the flanges 144,146.

The flange 146 is in the form of a cylinder that is movable towards andaway from the stationary flange 144, as indicated by the double-headedarrow 154, along the axis 130. The flange 146 is guidable along thesurface 148. With this arrangement, a belt receiving groove 156 isformed cooperatively by the surface 148 and flanges 144,146.

The shaft 128 has a corresponding mounting assembly 136′ with a smalldiameter portion 138′ bounded by larger diameter portions 140′,142′which are formed on stationary and movable flanges 144′,146′,respectively. A belt receiving groove 156′ is thereby defined that isalignable with the groove 156.

The shaft 128 is movable selectively in the direction of thedouble-headed arrow 158 towards and away from the shaft 126 to therebyselectively decrease and increase the spacing between the shafts126,128. With the belt/belt sleeve preform 12′ loosely trained aroundthe shafts 126,128, the shaft 128 can be moved away from the shaft 126to thereby tension the belt/belt sleeve preform 12′. By moving the shaft128 towards the shaft 126, tension on the trained belt/belt sleevepreform 12′ can be released to facilitate separation of the completedbelt/belt sleeve 12.

By moving the flanges 146,146′ towards and away from the stationaryflanges 144,144′ along the line of the double-headed arrows 154,154′,respectively, the width W of the grooves 156,156′ can be selectivelynarrowed and widened. With the belt/belt sleeve preform 12′ trainedaround the shafts 126,128, movement of the flanges 146,146′ toward theflanges 144,144′ can be carried out to capture the belt/belt sleevepreform 12′ between the larger diameter portions 140,142 on the shaft126 and 140′,142′ on the shaft 128. The movable flanges 146,146′ may bemoved synchronously, as by a pneumatic or hydraulic means 160, tothereby maintain the width W of the grooves 156,156′ at all times thesame.

The radial depth of the grooves 156,156′ is preferably such that atleast a part of the compression section 34 (FIG. 10) is received in thegroove and resides between the larger diameter portions 140,142 and140′,142′. If only the tension section 32 is accommodated by the grooves156,156′, removed scrap 161,161′ (FIG. 13), as discussed in detailhereinbelow, may not shift over to the larger diameter portions 140,142and 140′,142′ to follow movement thereof. As a result, the scrap mayinterfere with the basic cutting operations and may have to be removedas a procedure is being carried out. Further, a more positive grippingof the belt/belt sleeve preform 12′ can be effected with a deeper grooveconstruction.

The belt/belt sleeve preform 12′ is initially mounted by moving theshaft 128 towards the shaft 126 so that the belt/belt sleeve preform 12′can be loosely trained around the shafts 126,128 in the vicinity of thegrooves 156,156′. Thereafter, the shaft 128 is moved away from the shaft126 to tension the mounted belt/belt sleeve preform 12′. Preferably, thebelt tension is 400-1,200 N.

In this embodiment, as shown most clearly in FIG. 12, there are twospaced cutting locations at 162,162′ within a cutting space 164 boundedby an inner circumference 166 of the belt/belt sleeve preform 12′. Thecutting location 162 is on a length 168 of the belt/belt sleeve preformbetween the shafts 126,128 that is under running tension, i.e. pulled bythe driven shaft 126. The cutting location 162′ is on a length 170 ofthe belt/belt sleeve preform 12 between the shafts 126,128 that is in areturn path portion so as not to be under running tension.

A pushing component 172, as in the form of a synthetic resin roller, ismounted at the cutting location 162 and bears against the outside 18 ofthe belt/belt sleeve preform 12′ to reinforce the same during a cuttingoperation. A like pushing component 172′ is provided at the cuttinglocation 162′ to perform the same function.

Guide elements 174,176 are provided to bear captively on the spacedsides of the belt/belt sleeve preform 12′ to confine movement thereof,transverse to the length of the belt/belt sleeve preform 12′, during acutting operation. In this embodiment, there are two guide elements174,176 on each side of the belt/belt sleeve preform 12′.

Similar guide elements 174′,176′ are provided at the cutting location162′. The guide elements 174,174′,176,176′ are each in the form ofrollers which are rotated as the traveling belt/belt sleeve preform 12′bears thereagainst. Similarly, the pushing rollers 172,172′ arerotatable about axes 178,178′ as the traveling belt/belt sleeve preform12′ is borne thereagainst during a cutting operation.

The guide rollers 174,176′ each has a fixed rotational axis. Through anappropriate mechanism (not shown) the rollers 176,174′ are movabletransversely to the length of the belt/belt sleeve preform 12′selectively towards and away from the rollers 174,176′ to conform to theparticular width of the mounted belt/belt sleeve preform 12′. All of therollers 174,174′, 176,176′ can be simultaneously rotated as they bearagainst the traveling belt/belt sleeve preform 12′. As seen in FIG. 11,the pushing roller 172 resides vertically between the guide roller pairs174,176, with the pushing roller 172′ likewise residing verticallybetween the guide roller pairs 174′,176′.

The apparatus 120 is set up so that the outside 18 (FIG. 10) of thebelt/belt sleeve preform 12′ is borne against by the pushing rollers172,172′ with a predetermined pressure. The pressure between the pushingrollers 172, 172′ and the belt/belt sleeve preform 12′ can be adjustedin the range of 15-50 N. The movable rollers 176,174′ are adjustedtransversely to the belt/belt sleeve preform length to cause the rollerpairs 174,176 and 174′,176′ to either exert a captive pressure on thesides of the belt/belt sleeve preform 12′ or to be placed in closeproximity to the sides 20′, 22′.

With the apparatus 120 so set up, the motor 134 can be operated to drivethe shaft 126. This causes the belt/belt sleeve preform 12′ to travel inthe endless path which is predetermined by reason of the captivearrangement of the belt/belt sleeve preform 12′ within the grooves156,156′ and between the guide rollers 174,174′, 176,176′. Consequently,the belt/belt sleeve preform 12′ can be consistently guided without anysignificant deviation from a linear travel path. Accordingly, accuratecutting of the belt/belt sleeve preform 12′ is facilitated.

At the cutting location 162, the cutting blade 124 has a disk-shapedbody 180 that is inclined with respect to the belt/belt sleeve preform.The disk-shaped body 180 is rotated about its axis 182 in the directionof the arrow 184 through contact with the traveling belt/belt sleevepreform 12′. As previously noted, the cutting blade 124 is provided atthe cutting location in vertical coincidence with the pushing roller 172whereby the belt/belt sleeve preform 12′ is pinched therebetween duringa cutting operation. The body 180 of the cutting blade 124 obliquelypenetrates the belt/belt sleeve body from the inside thereof to producea bias cut with respect to the aforementioned reference plane P, thatbisects the belt/belt sleeve preform 12′ between the sides thereof andis orthogonal to the axes 130, 132.

The cutting blade 124 and pushing roller 172 are configured andrelatively positioned so that the cutting blade 124 cannot contact thepushing roller 172 during operation of the apparatus 120. As a result,the pushing roller 172 is not prone to being damaged by the cuttingblade 124, as a result of which it has a long useful life. Further, theaccuracy of the cutting can be maintained since the guiding componentswill not be damaged in use.

The cutting blade 124′ has a corresponding disk-shaped body 180′ that isrotatable around an axis 182′ in the direction of the arrow 184′. Thecutting blade 124′ cooperates with the pushing roller 172′ in the samemanner that the cutting blade 124 cooperates with the pushing roller172, as described above.

As noted previously, the bias cutting of the sides 20,22 occurs from theinside of the belt/belt sleeve preform 12′ up to the boundary locationBL. In this particular embodiment, the distance L3, representing thevertical dimension of the square cut side surface portions 46,48, isequal to L. The angle θ of attack for the cutting blades 124,124′ can beset as desired, and preferably is in the range of 20-60°.

A complete operation for forming the belt 12 in FIG. 2, using theapparatus 120, will now be described. As shown in FIG. 11, the movingmeans 160 is operated to move the flanges 146,146′ away from the flanges144,144′ so that the grooves 156,156′ are wider than the belt/beltsleeve preform 12′ to be trained around the shafts 126,128. Similarly,the guide rollers 176,174′ are moved away from the rollers 174,176′ toagain be spaced by a distance greater than the width of the belt/beltsleeve preform 12′ that is to be cut.

The shaft 128 is moved toward the shaft 126 to permit training of thebelt/belt sleeve preform 12′ around the shafts 126,128 and preliminaryalignment of the belt/belt sleeve preform 12′ at the grooves 156,156′.The shaft 128 is then moved away from the shaft 126 to tension thebelt/belt sleeve preform 12′. The moving means 160 is then operated toadvance the flanges 146,146′ towards the flanges 144,144′ to captivelymaintain the belt/belt sleeve preform 12′ within the grooves 156,156′.As previously noted, the grooves 156,156′ have a sufficient radialextent that a part of the compression rubber layer 24 residestherewithin. The square cut side surface portions 46,48 are thus captivebetween the larger diameter portions 140,142 and 140,142′. A portion ofthe compression rubber layer 24 likewise resides between the largerdiameter portions 140,142 and 140′,142′ so that the belt/belt sleevepreform is firmly captively held for consistent alignment.

The guide rollers 176,174′ are then moved towards the guide rollers174,176′ to captively engage the belt/belt sleeve preform 12′ at thecutting locations 162,162′.

The motor 134 can then be operated so that the tensioned belt/beltsleeve preform 12′ is driven in an endless travel path. At each cuttinglocation 162,162′, the cutting blades 124,124′ are obliquely pressedinto the compression rubber layer 24 at an angle θ relative to thereference plane P, with the belt/belt sleeve preform 12′ captivelysqueezed between the cutting blades 124,124′ and the pushing rollers172,172′. As a result, one side 20′ of the belt/belt sleeve preform 12′is bias cut by the one cutting blade 124, with the other side 22′ biascut by the other cutting blade 124′. As the cutting is carried out atthe cutting locations 162,162′, the belt/belt sleeve preform 12′ isstabily held and maintained in its linear travel path by the cooperatingcutting blades 124,124′, pushing rollers 172,172′ and guide rollers174,174′,176,176′.

Endless, ring-shaped scrap pieces 161, 161′ are separated from thebelt/belt sleeve preform 12′ by the cutting blades 124, 124′,respectively. At the moment of separation, the scrap pieces 161, 161′are squeezed axially outwardly relative to the shaft axes 130, 132 toengage and embrace the larger diameter portions 140,140′,142,142′ so asto thereby follow rotational movement of the shafts 126,128. The scrappieces 161, 161′ are actually wedged axially outwardly by a component ofthe squeezing force between the cutting blades 124,124′ and pushingrollers 172,172′. Alternatively, it can be considered that the scrappieces 161, 161′ are pushed out by a wedge shape at the leading end ofthe cutting blades 124,124′. The rounded corners 150,152 on the flanges144,146, and like rounded corners 150′,152′ on the flanges 144′,146′,facilitate transition of the scrap pieces 161, 161′ from a region at thesmall diameter portions 138,138′ to the larger diameter portions140,142,140′,142′. The scrap pieces 161, 161′ embrace, and continue tofollow movement of the shafts 126,128 until the tension upon thebelt/belt sleeve preform 12′ is released. Thus, there is littlepossibility that these scrap pieces 161, 161′ will interfere withoperation of the apparatus 120 during a cutting operation. At the sametime, the scrap pieces 161, 161′ can be conveniently recovered at thecompletion of the cutting operation by loosening the tension andeffecting simple separation of each as one piece.

At the completion of the cutting operation, rotation of the shaft 126 isstopped and the cutting blades 124,124′, guide rollers 176,174′, andflanges 146,146′ are returned to their starting positions. After thisoccurs, the belt tension can be released and the belt/belt sleeve 12 andscrap pieces 161, 161′ separated.

The invention contemplates many variations from the basic structure,described above, which is intended to be exemplary in nature only. Asone example, the belt construction is not limited to a belt having cogsin the compression section thereof. A double cogged belt could be madeusing the same inventive concepts, with cogs provided in the tensionsection 32 as well.

As another variation, while the pushing rollers 172,172′ act against theoutside of the belt/belt sleeve preform 12′, the pushing rollers172,172′ could operate on the opposite side at which, in thisembodiment, the cogs are formed, i.e., at the compression section 34.The pushing rollers 172, 172′ can also be made adjustable relative to anoperative belt/belt sleeve preform.

While two shafts 126,128 are described, three or more shafts would beused to guide movement of the belt/belt sleeve preform 12′, and can beoperated in other than a continuous linear path. Especially in the caseof a long belt, with a rectangular cross section, the belt can be biascut while the belt is running potentially around three or more shafts,so long as an appropriate tension is applied to the belt at each cuttinglocation.

While the mounting assemblies 136,136′ have been described with onestationary flange 144,144′ and one movable flange 146,146′, two fixedand/or two movable flanges could likewise be used to practice theinvention. It is desirable that the belt/belt sleeve preform 12′ bepositively captured between larger diameter portions and preferably, inthe case of the belt construction shown, with the compression rubberlayer between the larger diameter portions.

While the moving means 160 has been described to simultaneously move theflanges 146,146′, movement of the flanges 146,146′ may be carried outserially, or otherwise.

While cutting has been described at locations 162,162′, with onelocation of the belt/belt sleeve preform 12′ under running tension andthe other location in a return path/untensioned portion, both cuttinglocations could be at the same tensioned/untensioned location. If thistakes place, more preferably, the cutting would occur at a locationwhere the belt/belt sleeve preform 12′ is under running tension so as toavoid deflection of the belt during the cutting operation. Anysignificant deflection may compromise the accuracy of the bias cuttingprocess.

Further, the location of the cutting blades 124,124′ and pushingcomponents 172,172′ can be reversed.

As another modification, the rounding/radiussing of the corners150,152,150′,152′ can be omitted. This transition structure is desired,however. As an alternative to radiussing the corners, the corners can bechamfered, or otherwise modified.

The cutting blades 124,124′ may be either simultaneously operated, oroperated, one after the other, with a time lag.

As also noted above, the invention can be practiced on virtually anytype of the belt, whether or not it has cogs.

One specific process for making and forming one exemplary form of thebelt 12 will now be described. The load carrying cords 30 were made witharamid fibers, sold under the trademark TWARON. The cords 30 had adenier of 1,500 and were twisted in a reverse direction with respect tothe vertical direction with a final twist number of 19.7 times per 10 cmand an initial twist number of 15.8 times per 10 cm so as to attain a2×3 untreated cord with a total denier of 9,000. The untreated cord waspredipped in an isocyanate adhesive and dried at about 170-180° C. anddipped in an RFL solution. The cord was then subjected to elongationthermal fixing treatment at 200-240° C.

With respect to the reinforcing cloth layers 36,40, wide angle plainweave canvas was used with twisted yarns in which aramid fibers, soldunder the trademark TWARON, and polyethylene teraphthalate fibers weremixed with each other in a weight ratio of 50:50. The canvas was dippedin RFL solution and was subjected to heat treatment at 150° C. for twominutes. After that, the treated canvas was coated with a rubbercomposition using a friction coating process.

The compression and tension rubber layers 26,28 were made fromchloroprene rubber with embedded, aramid short staple fibers in anamount 25 weight parts per 100 weight parts of rubber. The cushionrubber layer 26 was made of chloroprene rubber with no short staplereinforcing fibers therein.

The cog pad 70 was made as follows. One piece of reinforcing cloth and asheet for the compression rubber layer were laminated together and seton a flat mold having cogs with alternating grooves and projections. Thesystem was pressurized at 75° C. Through this process, the cog pad 70was formed. Both ends of the cog pad were vertically cut off at crestportions.

The cog pad 70 was wound around an inner mother mold, made of vulcanizedrubber, attached to a cylindrical mold, and the ends butted to eachother. Load carrying cords 30, an unvulcanized rubber sheet for thetension rubber layer 26, and a reinforcing cloth layer 36 weresuccessively wound thereover. A jacket was placed over this assembly,which was set in a vulcanization vessel in which vulcanization wascarried out. The belt/belt sleeve preform 12′ was thus produced.

The resulting belt/belt sleeve 12′ was squarely cut with a cutter andfinished into individual belt preforms 12′ with a rectangular shape incross section. The belt preforms 12′ were arranged on the shafts 126,128of the belt forming apparatus 120 and operated as cutting took placethrough the compression rubber layer with the belt preforms 12′ backedby pushing rollers 172,172′. The boundary location BL was set at 100% Land the sides 20′,22′ bias cut with the cutting blades 124,124′. A rawedge cogged belt 12 was thus produced.

The sides 20,22 were cut at an angle of 42° with the short staplereinforcing fibers 58 exposed in flush relationship at the sides 20,22.The resulting raw edge cogged belt had a length of 300 mm and was set ona V pulley with a 90 mm diameter with a winding angle of 45°. A load of2.7 N was applied to one end of the belt and a load F, necessary to drawthe other end at a speed of 30 mm per second, was measured. The frictioncoefficient was found from this load F.

The above belt 12 was set up on a two shaft horizontal-type runningtester with a drive pulley having a 167.4 mm diameter and driven pulleywith a 133.0 mm diameter. The driven pulley had an applied load of 330kgf. The drive pulley was rotated at 3,000 rpm. After six hours of testrunning, a quantity of abrasion was measured by dividing the beltweight, which was measured six hours after test running, by the beltweight, which was measured before the start of the running test.

The results of the running test are described below. When a frictioncoefficient of a conventional belt, the surface of which was polished bysanding on a face which had been subjected to bias cutting, was 1, thefriction coefficient of the inventive belt was 1.4. When quantities ofabrasion were compared after the running test of six hours, the quantityof abrasion was 1 in the case of the conventional belt. On the otherhand, the quantity of abrasion was 0.7 for the inventive belt.

Further, the temperature of the side of the conventional belt was 135°C. after a running test of one hour. On the other hand, the temperatureof the side of the inventive belt was 126° C., which was lower than thetemperature of the conventional belt.

As previously noted, the belt of the present invention may be made sothat slippage of the belt, particularly as running is initiated, issmall, so that the quantity of abrasion at the time of initial startupcan be suppressed and the belt temperature can be maintained reasonablylow.

In FIGS. 17-19, a modified form of belt forming apparatus, according tothe present invention, is shown at 120′. The belt forming apparatus 120′consists of a main body 188 and driving and driven shafts 126′,128′,corresponding to the shafts 126,128 for the belt forming apparatus 120.The shafts 126′,128′ are rotatable around axis 130′,132′, respectively.The shafts 126′,128′ project in cantilevered fashion from the main body188 outwardly of the page in FIG. 17. At least one of the shafts126′,128′ is movable towards the other of the shafts 126′,128′ to changethe vertical spacing therebetween to facilitate mounting of a belt/beltsleeve preform 12′ therearound. This facilitates treatment of differentbelt sizes and also mounting and removal of belt/belt sleeve preforms12′ preparatory to, and after, processing.

A motor 134′ drives the shaft 126′ in the direction of the arrow 190around the axis 130′. As this occurs, a belt/belt sleeve preform 12′,trained around the shafts 126′,128′, is cause to move in an endlesspath, whereby the shaft 128′ is caused to rotate in the direction of thearrow 192 around its axis 132′. With this arrangement, the belt/beltsleeve preform 12′ is under running tension in the path portionindicated by the arrow 194 and returns untensioned in the path portionindicated by the arrow 196.

The belt/belt sleeve preform 12′ can have any configuration and is shownin an exemplary cog belt form, as previously described with respect toFIG. 2. The belt/belt sleeve preform 12′ is pre-cut so that the sides20′,22′ are parallel to each other and the body 14 is rectangular incross section. With a cogged construction, the cogs 44 (not shown indetail) are on the inner circumference 166 which bounds a cutting space164′.

The shafts 126′,128′ may have the same construction as the shafts126,128, previously described, or may have a different construction. Ina preferred form, the shaft 126′ has a groove 156″. The shaft 126′ has asmall diameter portion 138″ bounded by larger diameter portions140″,142″, corresponding in structure and function to like numberedparts in the prior embodiment. Similarly, the shaft 128′ has a smalldiameter portion 138′″ bounded by larger diameter portions 140′″,142′″.

The width of the grooves 156″,156′″ can be fixed or variable through amechanism as described for the belt forming apparatus 120, or by adifferent structure. With this arrangement, the belt/belt sleeve preform12′ can be trained around the shafts 126′,128′ and captive between thelarger diameter portions 140″,142″ and 140′″,142′″ to be consistentlyguided in a linear travel path.

A cutter 198 is provided in the cutting space 164 and is designed tobias cut the traveling belt/belt sleeve preform 12′ at cutting locations162″,162′″, corresponding to the aforementioned cutting locations162,162′.

At each cutting location 162″, 162′″, belt guide/supporting assemblies200,200′ are provided. The belt guide/supporting assembly 200 consistsof the same components as at the cutting location 162; namely thepushing component/roller 172 and guide elements/rollers 174,176.Similarly, the belt guide/supporting assembly 200′ consists of the samecomponents as at the cutting location 162′; namely the pushingcomponent/roller 172′ and the guide elements 174′,176′.

The cutter 198 consists of disk-shaped cutting blades 202,202′ attachedto a base 204 on a cantilevered arm 206 that projects into the cuttingspace 164′. The arm 206 has a length in the direction of thedouble-headed arrow 208 that is generally parallel to the rotationalaxes 130′,132′ for the shafts 126′,128′.

The belt forming apparatus 120′ includes a cutter controlling mechanismat 210 with a first stationary support table 212. A rotary base 214 ismounted to a slide 216, which is guided in translatory movement relativeto the table 212 along a line, indicated by the double-headed arrow 217.The base 214 supports a second table 218 that is movable therewithrelative to the slide 216 in rotation around a vertical axis 220. An armcarrier 222 consists of a base 224 and an elongate support 226 that iscantilever mounted to the base 224. The base 224 is guidinglytranslatable relative to the second table 218 along a line indicated bythe double-headed arrow 228, orthogonally to the line indicated by thearrow 217. The elongate support 226 has a free end 230, remote from thebase 224, to which the arm 208 is cantilever mounted. The length of thearm 208 extends substantially orthogonally to the length of the elongatesupport 226.

Servomotors, or other structure (not shown), are provided fortranslating the slide 216 relative to the first table 212, pivoting therotary base 214 relative to the slide 216, and translating the base 224relative to the second table 218. Through a programmed, coordinatedmovement, the cutter 198 on the arm 208 can be translated and reorientedwithin the cutting space 164.

The cutting blades 202,202′ have the same configuration, though this isnot a requirement. Each is in the form of a disk-shaped blade. With thisconfiguration, the entire circumference of each of the cutting blades202,202′ defines a cutting edge 232,232′.

The cutting blades 202,202′ are connected to the base 204 and arm 206 asfollows. In this embodiment, threaded fastening screws 233 (one shown)secure the cutting blades 202,202′ to the base 204 and arm 206. Thecutting blades 202,202′ have central axes 234,234′, respectively. Thecutting blades 202,202′ are offset axially from each other a distanceequal to the thickness of the base 204, but remain in partial radiallyoverlapping relationship, with the axes 234,234′ noncoincident. Thecutting blades 202,202′ are substantially parallel to each other. Theposition of the cutting blades 202,202′ is fixed with respect to eachother and the base 204 and arm 206.

By reason of being spaced axially from each other, the cutting blades202,202′ can be fixed positively without interference with each other.There is no possibility that the cutting blades 202,202′ will collide orotherwise interfere with each other. As a result, the blades 202, 202′are not as prone to being damaged, thereby avoiding the possibility ofregular maintenance, such as sharpening or replacement, associated withsuch a problem.

The cutting blades 202,202′ are fixed with the cutter 198 in a firststate, wherein the fastening screws 233 are tightened. The state of thecutter 198 can be changed by loosening the fastening screws 233, whichthereby allows the cutting blades 202,202′ to be pivoted around theirrespective axes 234,234′ to expose another portion of the circumferenceof the cutting edges 232, 232′ for use. Thereafter, the cutter 198 canbe changed back into the first state to fix the position of the cuttingblades 202,202′. The planes within which the cutting edges 233,233′reside are angled with respect to the line of the length of the arm 206.

A cutting operation will now be described with respect to the beltforming apparatus 120′, described above. As with the prior embodiment, arectangular belt/belt sleeve preform 12 can be set in the grooves156″,156′″ and trained around the shafts 126′,128′. One or both of theshafts 126,128′ can be moved to increase the spacing therebetween andthereby tension the belt/belt sleeve preform 12′ trained therearound.Preferably, the depth of the grooves 156″,156′″ is such that a part ofthe compression rubber layer 24 resides between the larger diameterportions 140″,142″ and 140′″,142′″. The pushing component/roller172,172′ and guide elements 174,174′,176,176′ are adjusted as previouslydescribed, or may be preset to a particularly belt/belt sleeve preformconfiguration.

Once the system is set up in this manner, the motor 134′ is operated.The cutter controlling mechanism 210 is then operated to bias cut oneside of the belt/belt sleeve preform with the cutting blade 202 andthereafter the other side with the cutting blade 202′.

More particularly, as seen in FIG. 18, the cutter 198 is driven in thedirection of the arrow 236 so that the protruding cutting blade 202′ isobliquely directed relative to the reference plane P, bisecting thebelt/belt sleeve preform 12′ between the sides 20′, 22′ thereof, to biascut the side 22′ at an angle θ. The cutter 198 is thereafter movedsubstantially oppositely to the one direction indicated by the arrow236, in the direction of the arrow 238, to similarly cut the other side20′ of the belt/belt sleeve preform 12′ to bias cut that side to thesame angle θ relative to the reference plane P.

In this embodiment, the cutting locations 162″,162′″ are atsubstantially the same vertical height so that the vertical position ofthe cutter 198 does not have to be changed. This is not a requirement,however. The pushing rollers 172,172′ reinforce the belt/belt sleevepreform 12′ during the cutting operation at each side of the belt/beltsleeve preform 12′. Through this arrangement, the belt/belt sleevepreform 12′ is positively held and maintained in its linear travel pathas the cutting operation is carried out to form the V-shaped belt 12.

By reason of the cutter 198 consisting of a unitary construction whereinthe cutting blades 202,202′ move as one piece, the cutter 198 can bemade relatively compact to function within the cutting space 164. As aresult, the overall system construction can be potentially simplifiedand also may be made relatively light in weight.

Further, by reason of the opposite movement of the cutter 198 within thenarrow horizontal dimension of the cutting space 164, a relatively smallamount of movement is required for the cutter 198, which potentiallyreduces processing time compared to the prior art apparatus.

Likewise, the support structure for the cutter 198, including thecantilevered arm 206, can be made relatively simple and compact.

The radially overlapping relationship of the cutting blades 202,202′also contributes to overall system compactness.

The ability to pivot the cutting blades 202,202′ avoids having toreplace the cutting blades 202,202′ on a frequent basis. By selectivelypivoting and refixing the cutting blades 202,202′, different portions ofthe cutting edges 232, 232′ can be presented as other portions thereofare damaged, wear, or otherwise become dull. Thus, potentially overallmaintenance costs and inconveniences can be reduced.

Since the cutter 198 operates on both sides of the belt/belt sleevepreform 12′ at the same vertical height, the same cutter 198 can be usedto process relatively short belts/belt sleeve preforms 12′.

The invention contemplates many variations from the basic structuredescribed above. Some of these modifications are described below. Theorientation of the cutting blades 202,202′, and the distance betweentheir respective axes, can be changed depending upon the bias cut angleand the cutting depth.

As in the prior embodiment, the belt/belt sleeve preform 12′ can betrained around more than the two shafts shown and will perform insubstantially the same manner.

The nature of the belt guide/supporting assemblies 200,200′ can bechanged from what is shown. The number and arrangement of pushingrollers and guide rollers can be changed. As just one example, thepushing rollers are arranged to push the outside surface of thebelt/belt sleeve preform 12′. The pushing rollers could be arranged topush the inside of the belt/belt sleeve preform 12′ at the region wherethe cogs are formed in the construction shown.

The particular configuration of the cutter control mechanism 210 isexemplary in nature only. Those skilled in the art could devisevirtually an unlimited number of different ways to reposition the cutter198, potentially departing significantly from the structure shownherein.

While the invention has been described with particular reference to thedrawings, it should be understood that various modifications could bemade without departing from the spirit and scope of the presentinvention.

1. A method of making a power transmission belt/belt sleeve, the methodcomprising the steps of: providing an endless belt/belt sleeve preformhaving an inside, an outside, and spaced sides and comprising acompression rubber layer, a tension rubber layer, and at least one loadcarrying member between the inside and outside of the belt/belt sleevepreform and having an inside and an outside and wherein a distance fromthe outside of the belt/belt sleeve preform to the outside of the loadcarrying member is defined as L; and bias cutting the spaced sidesrelative to a plane bisecting the belt/belt sleeve preform between thespaced sides from a boundary location that is spaced from the outside ofthe belt/belt sleeve preform by 90-100% of the distance L to the insideof the belt/belt sleeve perform, wherein the step of bias cuttingcomprises moving a cutter: a) in one direction through one of the insideand outside of the belt/belt sleeve perform to and through the other ofthe inside and outside of the belt/belt sleeve preform to reconfigureone of the spaced sides of the belt/belt sleeve preform; and b)generally oppositely to the one direction to reconfigure the other ofthe spaced sides of the belt/belt sleeve preform.
 2. The method ofmaking a power transmission belt/belt sleeve according to claim 1wherein the step of providing a belt/belt sleeve preform comprisesproviding a belt/belt sleeve preform with spaced sides that aresubstantially parallel to each other.
 3. The method of making a powertransmission belt/belt sleeve according to claim 1 further comprisingthe step of training the belt/belt sleeve around first and second spacedshafts and the step of bias cutting the spaced sides comprises biascutting the spaced sides at a location between the first and secondshafts wherein the belt/belt sleeve preform is under tension.
 4. Themethod of making a power transmission belt/belt sleeve according toclaim 2 further comprising the step of providing a pushing component ata first location to reinforce the belt/belt sleeve as the bias cuttingis performed.
 5. The method of making a power transmission belt/beltsleeve according to claim 4 wherein the step of training the belt/beltsleeve preform comprises training the belt/belt sleeve preform to definean inner circumference within which a cutting space is defined and thestep of bias cutting comprises bias cutting using a cutter and furthercomprising the steps of moving the cutter (a) in one direction withinthe cutter space to reconfigure one of the spaced sides of the belt/beltsleeve preform and (b) generally oppositely to the one direction withinthe cutting space to reconfigure the other of the spaced sides of thebelt/belt sleeve preform.
 6. A method of making a power transmissionbelt/belt sleeve, the method comprising the steps of: providing anendless belt/belt sleeve preform having an inside, an outside, andspaced sides and comprising a compression rubber layer, a tension rubberlayer, and at least one load carrying member between the inside andoutside of the belt/belt sleeve preform; training the belt/belt sleevepreform around at least first and second shafts having first and secondaxes; driving at least one of the shafts to thereby cause the belt/beltsleeve preform to travel in an endless path; providing a pushingcomponent at one of the inside and outside of the belt/belt sleevepreform at a first location; providing at least one guide element tobear against at least one of the sides of the belt/belt sleeve preformto confine movement of the belt/belt sleeve preform; providing a cutter;and directing the cutter against the belt/belt sleeve preform from theother of the inside and outside of the belt/belt sleeve preform at oradjacent to the first location so that: a) the one of the inside andoutside of the belt/belt sleeve preform is supported by the pushingcomponent; and b) the cutter moves in a direction through the other ofthe inside and outside of the belt/belt sleeve preform and thereafterthrough the one of the inside and outside of the belt/belt sleevepreform, to thereby reconfigure the belt/belt sleeve preform, whereinthe step of training the belt/belt sleeve preform comprises training thebelt/belt sleeve preform to define an inner circumference within which acutting space is defined and the step of directing the cutter comprisesmoving the cutter (a) in one direction within the cutting space toreconfigure one of the spaced sides of the belt/belt sleeve preform and(b) generally oppositely to the one direction within the cutting spaceto reconfigure the other of the spaced sides of the belt/belt sleevepreform.
 7. The method of making a power transmission belt/belt sleeveaccording to claim 6 wherein the first shaft has a small diameterportion between spaced larger diameter portions and the step of trainingthe belt/belt sleeve preform comprises placing the belt/belt sleevepreform between the spaced larger diameter portions.
 8. The method ofmaking a power transmission belt/belt sleeve according to claim 7wherein the step of training the belt/belt sleeve preform comprisesplacing the tension rubber layer and at least a part of the compressionrubber layer between the spaced larger diameter portions.
 9. The methodof making a power transmission belt/belt sleeve according to claim 6wherein the first and second axes are substantially parallel, and thestep of directing the cutter comprises causing the cutter to bias cutthe compression rubber layer relative to a reference plane that isorthogonal to the first and second axes.
 10. The method of making apower transmission belt/belt sleeve according to claim 9 wherein thestep of providing an endless belt/belt sleeve preform comprise providingan endless belt/belt sleeve preform wherein the spaced sides aresubstantially parallel to the reference plane.
 11. The method of makinga power transmission belt/belt sleeve according to claim 8 wherein thestep of providing a belt/belt sleeve preform comprises providing abelt/belt sleeve preform with a width at least nominally equal to adesired width of a completed power transmission belt.
 12. The method ofmaking a power transmission belt/belt sleeve according to claim 6wherein the step of providing a pushing component comprises providing apushing roller.
 13. The method of making a power transmission belt/beltsleeve according to claim 6 wherein the step of providing at least oneguide element comprises providing at least one guide roller at each ofthe spaced sides of the endless belt/belt sleeve preform.
 14. The methodof making a power transmission belt/belt sleeve according to claim 6wherein the step of providing a pushing component comprises providing apushing component at a location so that the pushing component cannot becontacted by the cutter as the cutter is directed against the belt/beltsleeve preform.
 15. The method of making a power transmission belt/beltsleeve according to claim 7 further comprising the step of changing aspacing between the larger diameter portions of the first shaft toaccommodate a width of the belt/belt sleeve preform.
 16. The method ofmaking a power transmission belt/belt sleeve according to claim 6wherein the load carrying member has an inside and an outside and thestep of providing a belt/belt sleeve preform comprises providing abelt/belt sleeve preform with a tension section defining the outside ofthe belt/belt sleeve preform and a compression section defining theinside of the belt/belt sleeve preform and wherein a distance from theoutside of the belt/belt sleeve preform to the outside of the loadcarrying member is defined as L and the spaced sides of the belt/beltsleeve preform are bias cut relative to a plane bisecting the belt/beltsleeve preform between the spaced sides from a boundary location that isspaced from the outside of the belt/belt sleeve preform by 90-100% ofthe distance L to the inside of the belt/belt sleeve preform.
 17. Themethod of making a power transmission belt/belt sleeve according toclaim 7 wherein the step of directing the cutter comprises causing thecutter to separate an endless portion of the belt/belt sleeve preformthat, upon being separated, is caused to embrace one of the spacedlarger diameter portions of the first shaft so as to follow rotationalmovement of the first shaft.
 18. The method of making a powertransmission belt/belt sleeve according to claim 16 wherein the step ofproviding an endless belt/belt sleeve preform comprises providing shortfibers with lengths extending between the sides of the belt/belt sleevepreform that are exposed at the bias cut spaced sides in the compressionrubber layer.
 19. The method of making a power transmission belt/beltsleeve according to claim 18 wherein the bias cut spaced sides each hasan area and the step of providing short fibers comprises providing shortfibers in an amount such that a combined area of the short fibersexposed at each spaced side is equal to 20-70% of the area of eachspaced side that is bias cut.
 20. The method of making a powertransmission belt/belt sleeve according to claim 6 wherein the step ofproviding a belt/belt sleeve preform comprises providing a belt/beltsleeve preform with a length and cogs spaced at regular intervals alongthe length of the belt/belt sleeve preform.
 21. The method of making apower transmission belt/belt sleeve according to claim 6 wherein thestep of providing a cutter comprises providing a cutter with first andsecond cutting blades that can be fixed relative to each other and torespectively configure the one and the other of the spaced sides of thebelt/belt sleeve preform.
 22. The method of making a power transmissionbelt/belt sleeve according to claim 21 wherein the step of providing acutter comprises providing a cutter with first and second disk-shapedcutting blades each having an axis, wherein the first and second cuttingblades are radially overlapped with the axes of the first and secondcutting blades being non-coincident.
 23. The method of making a powertransmission belt/belt sleeve according to claim 22 further comprisingthe steps of changing the cutter from a first state, pivoting the firstdisk-shaped cutting blade around its axis, and thereafter changing thestate of the cutter back into the first state to fix a position of thefirst disk-shaped cutting blade.
 24. The method of making a powertransmission belt/belt sleeve according to claim 6 wherein the step ofproviding a pushing component comprises providing a pushing component toreinforce the belt/belt sleeve preform with the cutter moving in the onedirection and further comprising the step of providing a second pushingcomponent to reinforce the belt/belt sleeve preform with the cuttermoving oppositely to the one direction.